Whilst Benjamin Netanyahu's cartoon bomb diagram (reminiscent of something out of Danger Mouse) may raise a few smirks, his UN speech succeeded in presenting a potentially game changing strategy in the Iranian crisis.
By defining a clear red line for Iran's nuclear programme, Netanyahu is clarifying the circumstances under which he would likely take military action, but also making clear to Iran and the international community how it can avoid that outcome.
Netanyahu has drawn his red line at the point before Iran has enough medium enriched uranium to produce fuel for a nuclear weapon if further enriched. He expects this point to be reached next spring or summer.
Approximately 225kg of 20% enriched uranium is reckoned to be needed to produce the 25kg of high enriched uranium required for one bomb. According to the last IAEA report in August, Iran had a stockpile of just over 90kg of 20% enriched uranium, having converted some of its stock into fuel for civilian use in the Tehran Research Reactor.
Between May and August Iran produced about 15kg of 20% enriched uranium a month, but also installed more centrifuges, giving it the potential to increase its rate of production. This is presumably the equation that has led Netanyahu to conclude that Iran will reach his red line by spring or summer of 2013.
Because enriching uranium becomes progressively easier the further you go, enriching up to 20% (medium enriched uranium) is most of the work towards weapons grade uranium, which is enriched to 90%. According to Netanyahu's assessment, once Iran crosses his red line it could further enrich the uranium to make weapons grade fuel in a matter of weeks. At that point, Netanyahu argues, it may be too late to stop it.
Netanyahu will hope his speech further galvanises the already considerable international efforts to pressure Iran through sanctions and diplomacy to stop enrichment, at least to the 20% level. Netanyahu knows that the international community is keen to prevent Iran getting a bomb, but also to prevent Israel from resorting to military action.
At the same time he is giving Iran a potential route out of the crisis. He is sending a message implicitly, that if Iran stops its production of 20% enriched uranium, or reduces its stockpile by shipping it out of Iran or converting it to fuel for non-military uses, Israel will not attack. This is close to what the P5+1 (the five permanent members of the UN Security Council and Germany) have been demanding in recent rounds of talks with Iran. Netanyahu is also implying that Israel will not act militarily if Iran continues only low enrichment up to three per cent.
The international focus around the issue will now build up in anticipation of the red line being reached next year. Though negotiations earlier this year between Iran and the P5+1 came to nothing, they are planning to hold more talks, and it will remain to be seen whether Netanyahu's ultimatum shifts Iranian behaviour.
Iran's progress towards the red line set out by Netanyahu is observable publicly through the IAEA's quarterly safeguards reports, which state how much enriched uranium Iran has amassed. All eyes will be on the next IAEA report, due at the end of November, to see how much Iran's stockpile of 20% enriched uranium has grown, and how much closer to the red line they have advanced.